Landing light for airplanes and the like



July 19-, 1938.

w. G. GRIMES LANDING. LIGHT FOR-'AIRPLANES AND THE LIKE Filed Nov. 4, 1935 M/EA/ 70/12 MI EN 5. E/WMES Ms A 7 TU/FA/E N NE Patented July 19, 1938 PATENT, OFFICE LANDING uon'r Fon AIRPLANES AND 'rnn Warren G. Grimes, Urbana, 01ml Application November 11, 1935, Serial no. 48,068

2 Claims.

This invention relates to a landing light for airplanes and the like. It is customary to provide an airplane with landing lights which are mounted on the end portions of the respective wings for movement into and out of a cavity in the lower side of the wing. Such a light fixture is usually pivotally mounted on the wing and is moved into and out of its extended or operative position by a manually. operated mechanism, and

which has a large wind resistance and is correspondngly heavy and expensive in construction.

This large size of the fixture is due in part at least to the manner in which the lamp is mounted in the fixture. The lamp usually employed for this purpose is removably mounted in a socket in the reflector portion of the fixture and is of such a character as to require a long socket, thereby requiring a large fixture to accommodate the lamp.

One object of the present invention is to provide a motor operated landing light having a relatively small fixture.

A further object of the invention is to provide such a landing light with power operated means for moving the same to and from its operative or extended position and for automatically interrupting its movement when it has reached either position.

A further object ofthe invention is to provide such a landing light with a motor driven operating mechanism which will be simple and compact in its construction and of light weight, so that it can be mounted within the airplane wing.

A further object of the invention is to provide such a landing light with means for so mounting the lampwithin the fixture that the latter may be made of small size as compared with the usual fixtures.

A further object of the invention is to provide such a landing light with a lamp unit comprising a lamp support and a lamp, which as a whole may be inserted in and removed from the fixture and in which the lamp will be automatically focussed by inserting the same in the fixture.

A further object of the invention is to provide such a lamp unit in which the lamp support may be of a light inexpensive construction to permit it to be discardedas a whole when .the lamp burns out.

Other objects of the invention may appear as the invention is described in detail.

In the accompanying drawing Fig; 1 is a side elevation, partly in section, of a landing light embodying my invention, showing the same the fixture itself is usually of relatively large sizemounted on an airplane wing; Fig. 2 is a detail section taken on the line 2-4 of Fig. 1; Fig. 3 is a detail of the lamp unit; and Fig. 4 is a circuit diagram. a

In the preferred embodiment of my invention, as shown in this drawing, the light fixture comprises a frame 5, preferably annular in form, and pivotally mounted on the wing 6 of the airplane adjacent to the edge of a cavity 1 in the lower side of the wing, so that the fixture may be moved into and out of the wing. Ordinarily the fixture is so mounted that when in its operative position 1 the light will beprojected forwardly and laterally with relation to the airplane. Mounted on and extending rearwardly from the annular frame of the fixture is a housing 8 having an inner reflecting surface, and mounted at the front of the frame 5 is a transparent closure or lens 9. Mounted on the frame 5 between the reflector housing 8 and the closure 9 is the lamp supporting member III, which is preferably annular in form and which fits snugly within the frame. A shallow lamp receiving member or socket H is arranged centrally of this annular supporting member and is connected therewith by radial arms I 2. The lamp receiving member ll faces rearwardly toward the reflector 8 and an incandescent lamp I3 is mounted in the receiving member and secured thereto in such a position that the filament of the lamp will be spaced equal distances from all portions of the periphery of the annular member l0 and will be in properly focussed relation to the reflector when the lamp support is mounted in the frame of the fixture. Preferably the lamp is permanentlysecured in the receiving member H, as by cementing the same therein. The supporting structure and the lamp thus constitute a single unit which may be inserted in and removed from theframe of the fixture as a unit.

The lamp {supporting member may be secured in the frame 5 in any suitable manner which will permit of its ready removal. In the particular construction illustrated the frame 5 has at its forward side an inwardly extending flange I 4 and the closure or lens 9 is clamped against this flange by a beveled ring IS. The annular member of the lamp support bears against the ring I5 and is held in engagement therewith by the reflector housing 8 which is detachably secured to the frame. In the present instance, the edge of the reflector housing is bent upon itself to form a channel l8 which receives the inturned edge of a clamping ring I! which is secured to the frame by screws I8. I! desired, a spacing member or washer 20 may be interposed between the refiector housing and the annular member [0. The lamp receiving member or socket II and the base 2| of the lamp are connected by leads 22 and 23 with conductor bars 24 and 25 arranged on opposite sides of one of the radial arms 12 of the support and insulated one from the other. The outer ends of these arms are connected by leads 28 with the motor circuit as will be hereinafter described. Thus it will be apparent'that by removing the reflector housing 8 and detaching the leads 26 from the terminals through which they are connected with the motor circuit the lamp unit as a whole may be removed and a new unit substituted therefor. The lamp support being of skeleton formation and of very light material and the lamp receiving member I I being of small size and shallow construction, inasmuch as it requires no attaching devices or the like, the lamp support may be produced at a very low cost. Further, the lamp which is used with this lamp support can be secured at a lower cost than the lamps ordinarily used for this purpose. Thus the lamp unit as a whole can be produced at a' cost which compares favorably with the cost of the ordinary lamp alone, thereby permitting the discarding of the lamp unit as a whole, when the lamp is burned out, without involving additional expense. The lamp being prefocussed by prop-' erly adjusting the same with relation to the lamp support and then permanently securing the same to the lamp support in its adjusted position it will be obvious that when the lamp unit is inserted in the fixture the lamp will be in proper focussed relation to the reflector.

The fixture may be mounted on the airplane and actuated by any suitable power operated mechanism which can be controlled from a remote point but I prefer to employ an electric motor for this-purpose. In the arrangement here illustrated an elongate part or arm 21 is rigidly secured to the frame of the fixture and forms a part of the fixture. This arm is provided near its point of connection with the frame with a pivot lug 28 by means of which it is pivotally mounted on the airplane wing. An operating member, such as a spur gear 29, is secured to a shaft 30 which is rotatably mounted in a bracket 3| and this member or gear is provided at a point spaced from its axis with a laterally extending stud 32 which extends into a guideway or channel 33 formed in the arm 21 and extending longitudinally thereof When the light fixture is in its retracted position, as shown in dotted lines in Fig. l, the arm 21 will extend substantially parallel with the wing and the stud 32 will be directly below the shaft 30. Upon the rotation of the gear in the direction indicated by the arrow the stud will act on the outer portion of the arm with a cam action to rotate the arm and fixture about the pivotal axis thereof and when the stud has completed approximately three quarters of a revolution the light fixture will have been moved 'to its operative position, as shown in full lines in Fig. 1. Duringthis movement the stud acts on the fixture through the arm with a long leverage and correspondingly great power to move the fixture against wind resistance and the movement of the fixture is correspondingly slow. To return the fixture to its retracted position the gear is rotated to carry the stud 32 through the remaining quarter of the revolution and during this relatively short movement the stud acts on the inner portion of the arm to quickly return the fixture to its retracted position, it being obvious that no resistance is oflered to the return movement of the fixture. The gear 29 meshes with a pinion 34 of an electric motor 35, this pinion being of small diameter so that the gear has a relatively slow movement.

When the light fixture reaches either its operative position or its retracted position its movement is automatically stopped, this being preferably accomplished by interrupting the operation of the motor. For this purpose two cams, 36 and 31, are secured to the shaft 30 for rotation with the gear and adapted to engage respectively with resilient contact members 38 and 39 of two motor switches which control two separate circuits which successively supply current to the motor. The cams are so arranged with relation to the stud 32 on the gear that the cam 36 will open its switch just as the fixture reaches its operative position and the cam 3'! will open its switch just asthe fixture completes its return movement.

'In'the circuit diagram of Fig. 4 I have shown the source of current supply as a battery B which is connected by a conductor 40 with a two way master switch S. One side of this switch is connected by conductors 4| and 42 with the resilient contact member 38 of one of the motor switches. The stationary contact 43 of that motor switch is connected by a conductor 44 with one side of the motor 35 and the other side of the motor is connected by the .conductor 45 with the battery. The lamp I3 is connected with the conductor 4|, between the motor switch 38 and the master switch, and with the conductor 45. The other side of the master switch S is connected by a conductor 46 with the-resilient contact member 39 of the other motor switch and the stationary contact member 41 of this motor switch is also connected with the motor by the conductor 44. When the handle of the master switch is moved to the dotted line position a the current will fiow from the battery through the master switch and motor switch 38-43 to the motor, thus energizing the motor and initiating the movement of the light fixture. At the same time the circuit is closed through the lamp l3 so that the fixture is illuminated at the beginning of its outward movement. When the fixture has reached its outermost or operative position the cam 36 will act on the contact member 38 to break the circuit through the motor and thus interrupt the movement of the light fixture, but the lamp being connected with the motor circuit in advance of the switch 38 will not be affected by the stopping of the motor and its illumination will continue-until its circuit is opened at the master switch. When the landing has been effected and the light fixture is to be retracted the master switch is moved to the dotted line position b, thus closing the circuit through the motor switch 39, without closing the circuit through the lamp, and when the fixture has reached its retracted position the cam 31 will engage the yieldable contact member 39 and open this motor switch, thereby again interrupting the operation of the motor. The cam 31 will continue to hold the switch in its open position and the handle of the master switch may be left in position b or returned to neutral. The cam'36 having been moved out of engagement with the switch member 38 by the second opera- The motor for operating the fixture may be of a very small size and of light weight, the operating mechanism is of simple compact construction and of light weight and the fixture itself, including the lamp unit, is of small size so that it has little wind resistance and is also of light weight. As a result the complete apparatus is of very light weight and of compact form so that it can be easily mounted on the airplane wing, and will add little weight thereto. As a matter of fact the weight of the motor and the operating mechanism is less than-the weight of the usual hand operated mechanisms heretofore employed for operating landing lights. Further, the use of the motor operated mechanism avoids the necessity of running cables through the wings and providing the necessary connections therefor, which is often objectionable.

While I have shown and described one embodiment of my invention I wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now'fully described my invention, what I claim as new and desire to secure by, Letters Patent, is:

1. In a prefocussed lamp unit for a light flxture having a reflector, said unit comprising a lamp support of skeleton form adapted to be removably mounted at its outer edge on said flxture adjacent the peripheral edge of said reflector and in an enact predetermined position with relation to said fixture, a lamp receiving member immovably mounted on said lamp support near the center thereof, said lamp receiving member projecting beyond the side of said lamp support opposite said reflector and facing said reflector, and a lamp immovably mounted in said lamp receiving member in an exact predetermined relation to said lamp supportwhich will cause said lamp to be supported in focussed relation to said reflector when said lamp support is mounted in said predetermined position on said fixture.

2. A light fixture comprising an annular frame having means for mounting the same on a supporting structure, an annular lamp supporting element removably mounted on said frame, means carried by said frame to limit the movement of said lamp supporting element in one direction with relation to said frame, a reflector supported at its forward edge on said frame and acting on said lamp supporting element to hold the latter in flrm engagement with said movement limiting means, means for detachably securing said reflector to said frame, and a lamp immovably mounted on said annular lamp supporting element near the center thereof andso spaced therefrom that it will be in i'o'cussed relation to said reflector when said flxture is assembled.

WARREN G. GRIMES. 

